Caloric Restriction directs topological chromatin reorganization to enter and maintain enhanced quiescence

热量限制指导拓扑染色质重组进入并维持增强的静止状态

• 批准号: 10295030
• 负责人: Elisa Enriquez Hesles
• 金额: $ 3.47万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10295030
• 关键词: ATAC-seq; Acetate-CoA Ligase; Acetyl Coenzyme A; Address; Age; Aging; Animal Model; Architecture; Automobile Driving; Bioinformatics; Biological Models; Buffers; Caloric Restriction; Cardiovascular Diseases; Cell Cycle; Cell Death; Cell physiology; Cells; Chromatin; Chromatin Structure; Chronic Disease; Chronology; Complex; Development; Disease; Gene Activation; Gene Expression; Genes; Genetic Transcription; Glucose; Goals; Hi-C; Histone Deacetylase; Histones; Impairment; Intervention; Longevity; Maintenance; Malignant Neoplasms; Mediating; Modeling; Molecular; Nerve Degeneration; Nuclear; Nucleotides; Organizational Change; Phase; Phenotype; Population; Prevalence; Process; Production; Proteins; Psychological reinforcement; Regimen; Research; Research Personnel; Resolution; Reverse Transcriptase Polymerase Chain Reaction; Risk Factors; Role; SAGA; Saccharomyces cerevisiae; Saccharomycetales; Serine; Structure; Testing; Threonine; Training Programs; Transcription Coactivator; Transcription Repressor; XBP1 gene; Yeasts; cell age; cellular longevity; chromatin remodeling; dietary; epigenome; experimental study; healthspan; healthy aging; histone acetyltransferase; improved; insight; interest; mimetics; mutant; novel; prevent; promoter; response

PROJECT SUMMARY/ABSTRACT Aging is the leading risk factor for chronic diseases such as cardiovascular disease, cancer and neurodegeneration. As the U.S. population continues to grow older, the prevalence of these diseases will increase. Therefore, determining the mechanisms underpinning pro-longevity interventions, such as caloric restriction (CR) is an important priority. Although CR intervention improves factors contributing to cellular demise in the aging process, its impact on chromatin remodeling remains understudied. My dissertation is to understand the establishment and maintenance of quiescent chromatin architecture in the context of Saccharomyces cerevisiae chronological aging and its response to longevity interventions like CR. Understanding these changes in chromatin organization will facilitate the development of novel interventions, mimicking the beneficial effects of CR on longevity. In preliminary experiments, I have found that CR optimizes transcription conditions with abundant intracellular nucleotide, acetyl-CoA levels, and acetyl-CoA synthetase (Acs2), as cells start the transition into quiescence. I propose to elucidate the mechanism of how these conditions induce a transcriptional regulatory cascade that enhances quiescence. First in Aim 1, I will define how CR temporally and structurally enhances chromatin compaction as cells enter quiescence. Second, I will test the hypothesis that CR induces the early wave of transcription via acetyl-CoA accumulation by Acs2. This accumulation then results in histone hyperacetylation at relevant target promoters by Gcn5 histone acetyltransferase complex (SAGA). Third, I will test the contribution of nucleotide buffering to transcription and the later establishment of repressive chromatin in quiescence. These studies will provide mechanistic insights of CR's role in establishing quiescence during chronological aging. Chromatin compaction is vital to maintaining quiescence, yet the architectural changes that occur during aging or in response to CR are unknown. Therefore, in Aim 2, I will characterize the maintenance of repressive chromatin structure during chronological aging. I hypothesize that transcriptional repressors and chromatin architectural proteins become depleted with age, and thus detrimental to quiescence. First, I will detect breakdown of repressive chromatin structure in aged cells and its effect on transcription using a combination of ATAC-Seq and PRO-Seq. Second, I will characterize the depletion of chromatin factors in CLS using tandem mass tagging (TMT) experiments. Third, I will determine if chromatin openness during quiescence drives cell cycle re-entry or cell death in snf1∆ and gcn5∆ mutants. These experiments will define CR's impact on the temporal and structural maintenance of repressive chromosomal architecture during aging.

项目概要/摘要 衰老是心血管疾病、癌症等慢性疾病的主要危险因素 随着美国人口继续老龄化，这些疾病的患病率将会增加。 因此，确定支持长寿干预措施的机制，例如热量。 尽管 CR 干预可以改善导致细胞死亡的因素，但限制 (CR) 是一个重要的优先事项。 在衰老过程中，它对染色质重塑的影响仍未得到充分研究。 酵母菌中静态染色质结构的建立和维持 酿酒酵母按时间顺序衰老及其对 CR 等长寿干预措施的反应。 染色质组织中的变化将促进新型干预措施的开发，模仿有益效果 CR 对长寿的影响。 在初步实验中，我发现CR优化了转录条件，具有丰富的细胞内 当细胞开始过渡到静止状态时，核苷酸、乙酰辅酶 A 水平和乙酰辅酶 A 合成酶 (Acs2) 会发生变化。 提议阐明这些条件如何诱导转录调控级联的机制 首先，在目标 1 中，我将定义 CR 如何在时间上和结构上增强染色质。 其次，我将检验 CR 诱导早期波的假设。 Acs2 通过乙酰辅酶 A 积累进行转录，然后这种积累导致组蛋白高度乙酰化。 Gcn5组蛋白乙酰转移酶复合物（SAGA）的相关目标启动子第三，我将测试贡献。 核苷酸缓冲对转录的影响以及随后在静止状态下建立抑制性染色质。 研究将为 CR 在按时间顺序衰老过程中建立静止中的作用提供机制见解。 染色质压缩对于维持静止至关重要，但衰老过程中发生的结构变化 或对 CR 的反应是未知的，因此，在目标 2 中，我将描述维持压制的特征。 我勇敢地面对转录抑制因子和染色质在衰老过程中的染色质结构。 建筑蛋白会随着年龄的增长而耗尽，从而导致疼痛静止。首先，我将检测。 衰老细胞中抑制性染色质结构的分解及其对转录的影响 其次，我将使用串联技术描述 CLS 中染色质因子的消耗。 第三，我将确定静止期间染色质开放是否驱动细胞。 snf1Δ 和 gcn5Δ 突变体的循环重新进入或细胞死亡这些实验将定义 CR 对 衰老过程中抑制性染色体结构的时间和结构维持。